The present disclosure relates to approaches for reformulating green pyrotechnic compositions so as to eliminate environmentally objectionable perchlorate ingredients while still providing acceptable performance when compared to in-service signal flare devices.
Pyrotechnics are used in a variety of applications. One such application is colored signal flares. Many such pyrotechnic flare compositions include chlorate or perchlorate oxidizers. Residual perchlorates from these devices may be absorbed into groundwater and require remediation.
In the past, the vast majority of red, green and yellow signal flares have used perchlorate ingredients to produce their desired colors. This has contributed to an increase in the total concentration of perchlorate residues at various sites, such as military and industrial sites, and to their generally higher than desired concentration in drinking water supplies. Clearly, any methods that can be used to eliminate the perchlorates and minimize any other chlorine-containing ingredients would be an environmentally noteworthy advance in the state of the art.
The U.S. Navy has an in-service green flare perchlorate-containing composition (IS G). IS G includes approximately twenty-one weight percent (21%) Granulation 18 magnesium fuel, approximately seven weight percent (7%) copper, approximately thirty-two point five weight percent (32.5%) potassium perchlorate, approximately twenty-two point five weight percent (22.5%) barium nitrate, approximately twelve weight percent (12%) polyvinyl chloride (PVC), and approximately five weight percent (5%) binder. The binder including the range of approximately seventy percent (70%) to approximately eighty percent (80%) Epon™ Resin 813 epoxy and within the range of approximately twenty percent (20%) to approximately thirty percent (30%) Versamid® 140 curing agent. Accordingly, it was this composition that formed the starting point in the new perchlorate-free green signal flare formulations disclosed in the present patent application.